Myosin V is a double-headed molecular motor that moves processively along actin filaments. Its processivity requires coordination between its two heads to keep their ATPase cycles out of phase, preventing both heads from detaching actin simultaneously. However, the kinetic scheme that two-headed myosin V takes during its processive run has long been debated. To address this issue, we studied the processivity (velocity and run length) of myosin V at multiple substrate conditions under zero load. We found that increasing [ATP] decreased the run length of myosin V, and a high phosphate concentration in the solution decreased both velocity and run length, as well as marlcedly increased the ratio of backsteps. Theses results are well explained by a lunetic model (Baker et al., 2004) in which myosin V proceeds through a branched kinetic pathway.

This highly authoritative volume highlights the remarkable superfamily of molecular motors called myosins, which are involved in such diverse cellular functions as muscle contraction, intracellular transport, cell migration and cell division. In a timely compilation of chapters written by leading research groups that have made key discoveries in the field, the current understanding of the molecular mechanisms and biological functions of these intriguing proteins is explored.

Since the discovery of actin by Straub in the 1950’s and the pioneering work of Oosawa on actin self-assembly in helical laments in the 1960’s, many books and conference proceedings have been published. As one of the most essential p- teins in life, essential for movement in organisms rangingfrom bacteria to higher eukaryotes, it is no surprise that actin has fascinated generations of scientists from many different elds. Actin can be considered as a “living treasure” of biology; the kinetics and thermodynamics of self-assembly, the dissipative nature of actin po- merization, the molecular interactions of monomeric and polymerized actin with regulators, the mechanical properties of actin gels, and more recently the force p- ducing motile and morphogenetic processes organized by the actin nanomachine in response to signaling, are all milestones in actin research. Discoveries that directly derive from and provide deeper insight into the fundamental properties of actin are constantly being made, making actin an ever appealing research molecule. At the same time, the explosion in new technologies and techniques in biological sciences has served to attract researchers from an expanding number of disciplines, to study actin. This book presents the latest developments of these new multiscale approaches of force and movement powered by self-assembly processes, with the hope to opening our perspectives on the many areas of actin-based motility research.

A Unified Microscopic Approach to Analyzing Complex Processes in Molecular MotorsMotor Proteins and Molecular Motors explores the mechanisms of cellular functioning associated with several specific enzymatic molecules called motor proteins. Motor proteins, also known as molecular motors, play important roles in living systems by supporting cellular

This thesis offers a unique guide to the development and application of ultrasensitive optical microscopy based on light scattering. Divided into eight chapters, it covers an impressive range of scientific fields, from basic optical physics to molecular biology and synthetic organic chemistry. Especially the detailed information provided on how to design, build and implement an interferometric scattering microscope, as well as the descriptions of all instrumentation, hardware interfacing and image processing necessary to achieve the highest levels of performance, will be of interest to researchers now entering the field.

Biophysics is a rapidly-evolving interdisciplinary science that applies theories and methods of the physical sciences to questions of biology. Biophysics encompasses many disciplines, including physics, chemistry, mathematics, biology, biochemistry, medicine, pharmacology, physiology, and neuroscience, and it is essential that scientists working in these varied fields are able to understand each other's research. Comprehensive Biophysics, Nine Volume Set will help bridge that communication gap. Written by a team of researchers at the forefront of their respective fields, under the guidance of Chief Editor Edward Egelman, Comprehensive Biophysics, Nine Volume Set provides definitive introductions to a broad array of topics, uniting different areas of biophysics research - from the physical techniques for studying macromolecular structure to protein folding, muscle and molecular motors, cell biophysics, bioenergetics and more. The result is this comprehensive scientific resource - a valuable tool both for helping researchers come to grips quickly with material from related biophysics fields outside their areas of expertise, and for reinforcing their existing knowledge. Biophysical research today encompasses many areas of biology. These studies do not necessarily share a unique identifying factor. This work unites the different areas of research and allows users, regardless of their background, to navigate through the most essential concepts with ease, saving them time and vastly improving their understanding The field of biophysics counts several journals that are directly and indirectly concerned with the field. There is no reference work that encompasses the entire field and unites the different areas of research through deep foundational reviews. Comprehensive Biophysics fills this vacuum, being a definitive work on biophysics. It will help users apply context to the diverse journal literature offering, and aid them in identifying areas for further research Chief Editor Edward Egelman (E-I-C, Biophysical Journal) has assembled an impressive, world-class team of Volume Editors and Contributing Authors. Each chapter has been painstakingly reviewed and checked for consistent high quality. The result is an authoritative overview which ties the literature together and provides the user with a reliable background information and citation resource